European Journal of Organic Chemistry

Cover image for Vol. 2014 Issue 27

Early View (Online Version of Record published before inclusion in an issue)

Editor: Haymo Ross, Deputy Editor: Susan Wilkinson

Impact Factor: 3.154

ISI Journal Citation Reports © Ranking: 2013: 14/58 (Chemistry Organic)

Online ISSN: 1099-0690

Associated Title(s): Advanced Synthesis & Catalysis, Asian Journal of Organic Chemistry

VIEW

  1. 1 - 92
  1. Full Papers

    1. Asymmetric Transfer Hydrogenation

      Microwave-Enhanced Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)imines

      Óscar Pablo, David Guijarro and Miguel Yus

      Article first published online: 18 SEP 2014 | DOI: 10.1002/ejoc.201402884

      Thumbnail image of graphical abstract

      Microwave irradiation promotes the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in 2-propanol catalysed by a ruthenium complex bearing an achiral β-amino alcohol as ligand. After desulfinylation, α-branched primary amines containing aromatic, heteroaromatic and aliphatic substituents are obtained in excellent yields and with enantiomeric excesses of up to 96 %.

  2. Microreviews

    1. Manipulating Peptide Structures

      Heterogeneous Foldamers from Aliphatic–Aromatic Amino Acid Building Blocks: Current Trends and Future Prospects

      Roshna V. Nair, Kuruppanthara N. Vijayadas, Arup Roy and Gangadhar J. Sanjayan

      Article first published online: 18 SEP 2014 | DOI: 10.1002/ejoc.201402877

      Thumbnail image of graphical abstract

      This review is an effort to cover this rapidly developing field of foldamer science involving aliphatic-aromatic conjugate building blocks and to envisage its future perspectives.

  3. Full Papers

    1. Total Synthesis

      Synthesis of the Sesquiterpenes Albicanol, Drimanol, and Drimanic Acid, and the Marine Sesquiterpene Hydroquinone Deoxyspongiaquinol

      Matthias Göhl and Karlheinz Seifert

      Article first published online: 18 SEP 2014 | DOI: 10.1002/ejoc.201402873

      Thumbnail image of graphical abstract

      The valuable building blocks in the synthesis of various meroterpenes (+)-albicanyl acetate, (+)-albicanol, (+)-drimanol, and (+)-drimanic acid were synthesized through a TiIII-mediated radical cyclization cascade starting from all-trans-farnesol. (+)-Drimanic acid was transformed into the marine sesquiterpene hydroquinone deoxyspongiaquinol. Thus, five natural products were synthesized.

    2. Bioorganic Chemistry

      Diffusion-Ordered Spectroscopy and Saturation Transfer Difference NMR Spectroscopy Studies of Selective Interactions between ELAV Protein Fragments and an mRNA Target

      Francesca Vasile, Daniela Rossi, Simona Collina and Donatella Potenza

      Article first published online: 17 SEP 2014 | DOI: 10.1002/ejoc.201403014

      Thumbnail image of graphical abstract

      The first diffusion-ordered spectroscopy (DOSY) and saturation transfer difference (STD) NMR spectroscopy studies of RNA fragments and peptides (P1P4) derived from Embryonic Lethal Abnormal Vision (ELAV) proteins are reported, and insights into the interaction mechanism are presented. The information derived from these results will allow us to design ELAV peptide mimics that can bind to RNA targets.

    3. Base-Initiated Rearrangement

      Synthesis of 1,2-Diols and Their Base-Initiated Rearrangement to Butyrolactones

      Mauro Moliterno, Cristiana Margarita, Silvia Panarello, Riccardo Salvio and Marco Bella

      Article first published online: 17 SEP 2014 | DOI: 10.1002/ejoc.201402853

      Thumbnail image of graphical abstract

      Unsaturated 3-hydroxybutyrolactones (isotetronic acids) have been prepared by a novel rearrangement of 1,2-diols involving an unusual alkyl shift. A possible mechanism is described with the aid of DFT calculations.

    4. Lewis Acid Promoted Cyclization

      Six-Membered Ring Formation from Lewis Acid Promoted Reactions of 2-Substituted 2-Alkenyl Amides and Esters of Ethenetricarboxylate

      Shoko Yamazaki, Kohta Ueda, Yugo Fukushima, Akiya Ogawa and Kiyomi Kakiuchi

      Article first published online: 17 SEP 2014 | DOI: 10.1002/ejoc.201402637

      Thumbnail image of graphical abstract

      The Lewis acid promoted reactions of 2-substituted 2-propenyl amides and allenyl esters of ethenetricarboxylate gave six-membered-ring heterocycles as the major products. In the reactions of the 2-substituted 2-propenyl amides, elimination products were obtained selectively instead of the substitution products.

  4. Short Communications

    1. C–C Coupling

      Nickel-Catalyzed Kumada Coupling of Benzyl Chlorides and Vinylogous Derivatives

      Rita Soler-Yanes, Manuel Guisán-Ceinos, Elena Buñuel and Diego J. Cárdenas

      Article first published online: 16 SEP 2014 | DOI: 10.1002/ejoc.201403007

      Thumbnail image of graphical abstract

      Benzyl and allyl chlorides are efficiently coupled with alkylmagnesium reagents by using a simple Ni precursor at low temperature with a low catalyst loading (acac = acetylacetonate, TMEDA = N,N,N′,N′-tetramethyl-1,2-ethylenediamine).

  5. Full Papers

    1. Asymmetric Sulfinylation

      DMAP-Catalysed Sulfinylation of Diacetone-D-Glucose: Improved Method for the Synthesis of Enantiopure tert-Butyl Sulfoxides and tert-Butanesulfinamides

      Ahmed Chelouan, Rocío Recio, Ana Alcudia, Noureddine Khiar and Inmaculada Fernández

      Article first published online: 16 SEP 2014 | DOI: 10.1002/ejoc.201402673

      Thumbnail image of graphical abstract

      An improved method for the tert-butanesulfinylation of diacetone glucose with tert-butanesulfinyl chloride is reported. The resulting (RS)-DAG sulfinate ester 2RS is an excellent C- and N-sulfinylating agent that can be used for the synthesis of relevant enantiopure sulfoxides and (SS)-tert-butanesulfinamides.

    2. Cross-Coupling Reactions

      Suzuki–Miyaura Coupling of Aryl Chlorides with Arylboronic Acids Using the Morpholine–NiCl2 Catalyst System

      Taichi Abe, Takashi Mino, Kohei Watanabe and Masami Sakamoto

      Article first published online: 16 SEP 2014 | DOI: 10.1002/ejoc.201402881

      Thumbnail image of graphical abstract

      We report morpholine–NiCl2 as a new catalyst system for the Suzuki–Miyaura coupling of aryl chlorides with aryl- or alkenylboronic acids to give biaryl compounds. This catalyst system is easy to apply on a large scale because of its easy preparation and the use of inexpensive reagents, and has broad substrate scope. Analysis of the residual nickel showed only 9.7 ppm remaining after work-up.

  6. Short Communications

    1. Chain Extension

      Chain Extension of Boronic Esters with Lithiooxiranes Generated by Sulfoxide–Metal Exchange – Stereocontrolled Access to 2°/2°, 2°/3°, and 3°/3° Vicinal Diols and Related Compounds

      Embarek Alwedi, Lev N. Zakharov and Paul R. Blakemore

      Article first published online: 16 SEP 2014 | DOI: 10.1002/ejoc.201403105

      Thumbnail image of graphical abstract

      Chain extension of boronic esters with lithiated epoxides generated from sulfinyl epoxides by sulfoxide–lithium exchange enables stereocontrolled synthesis of β-alkoxyboronates, which can be converted to 2°/2°, 2°/3°, or 3°/3° vicinal diols. The method performs best when more highly substituted sulfinyl epoxides are employed as homologation reagents.

    2. Decarboxylation

      Decarboxylation of a Wide Range of Amino Acids with Electrogenerated Hypobromite

      Roman Matthessen, Laurens Claes, Jan Fransaer, Koen Binnemans and Dirk E. De Vos

      Article first published online: 16 SEP 2014 | DOI: 10.1002/ejoc.201403112

      Thumbnail image of graphical abstract

      An electrochemical system is developed that allows the selective decarboxylation of a wide range of amino acids. Valuable nitriles are obtained in high yields in a single step by using bromide salts as both redox mediators and supporting electrolytes. The product selectivity of lysine can be tuned towards nitriles, amines, or amides.

  7. Full Papers

    1. Reaction Mechanisms

      Addition–Elimination versus Direct Substitution Mechanisms for Arene Chlorination

      Boris Galabov, Gergana Koleva, Jing Kong, Henry F. Schaefer III and Paul v. R. Schleyer

      Article first published online: 15 SEP 2014 | DOI: 10.1002/ejoc.201402765

      Thumbnail image of graphical abstract

      The present comprehensive DFT computational exploration of aromatic chlorination predicts that the barriers for the addition of Cl2 to benzene, toluene and naphthalene catalyzed by HCl in the gas phase and in simulated CCl4 solution can be even lower than the barriers for direct substitution. Moreover, substitution products also can arise from stepwise Cl2 addition/HCl elimination routes.

    2. Prins Reactions

      Toward Pyridine–Heterocycle Patterns through Prins and Aza-Prins Cyclisations: Application to a Short Synthesis of (±)-Anabasine

      Olivier Colin, Christine Greck, Damien Prim and Christine Thomassigny

      Article first published online: 15 SEP 2014 | DOI: 10.1002/ejoc.201402971

      Thumbnail image of graphical abstract

      The (aza)-Prins cyclisation has been applied to several pyridine carbaldehydes, opening the way to an easy access to bisheterocycles. The method was effective for the synthesis of anabasine in two steps.

  8. Short Communications

    1. Tandem Reactions

      Tandem α-Alkylation/Asymmetric Transfer Hydrogenation of Acetophenones with Primary Alcohols

      Oleksandr O. Kovalenko, Helena Lundberg, Dennis Hübner and Hans Adolfsson

      Article first published online: 15 SEP 2014 | DOI: 10.1002/ejoc.201403032

      Thumbnail image of graphical abstract

      One catalyst – one pot – two reactions. Acetophenones are initially alkylated with primary alcohols by the borrowing hydrogen methodology. The alkylation products are directly converted to enantiomerically enriched secondary alcohols.

    2. Domino Reactions

      Assembly of a 1H-Pyrrol-2(5H)-one Core through a Cascade Ugi Reaction/5-endo-dig Carbocyclization/Retro-Claisen Fragmentation Process

      Anatoly A. Peshkov, Vsevolod A. Peshkov, Zhenghua Li, Olga P. Pereshivko and Erik V. Van der Eycken

      Article first published online: 15 SEP 2014 | DOI: 10.1002/ejoc.201402723

      Thumbnail image of graphical abstract

      A cascade transformation involving the Ugi reaction followed by 5-endo-dig carbocyclization and retro-Claisen fragmentation providing access to a 1H-pyrrol-2(5H)-one core is described.

  9. Full Papers

    1. Fluorinated Oligoporphyrins

      Synthesis of Highly Fluoroalkyl-Functionalized Oligoporphyrin Systems

      Lukas Felix, Ugur Sezer, Markus Arndt and Marcel Mayor

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402816

      Thumbnail image of graphical abstract

      Massive but volatile molecules have been obtained by functionalizing the periphery of oligoporphyrins with highly fluorinated alkyl chains. The statistical nature of the reaction gives libraries consisting of molecules with well-defined masses but small structural diversity. Laser desorption and post-ionization studies demonstrated the potential of these libraries as sources of heavy particles.

    2. Protecting Groups

      Efficient Transfer of Chelating Amides into Different Types of Esters and Lactones

      Uwe Jakob, Stephan Mundinger and Willi Bannwarth

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402843

      Thumbnail image of graphical abstract

      Due to their high resonance energy, amides are generally very stable towards solvolysis. However, bispicolylamides can be activated for alcoholysis by an unusual metal coordination involving the electron pair of the amide nitrogen. Herein, we widened the scope of the reaction by transforming the amides into a range of esters and lactones.

  10. Short Communications

    1. Spiroindolinones

      Regio- and Chemoselective Formation of Spiroindolinone–Isoindolinone by a Palladium-Catalyzed Buchwald–Hartwig Addition–Elimination Sequence

      Himanshu H. Butani, Dipak D. Vachhani, Umed C. Bhoya, Anamik K. Shah and Erik V. Van der Eycken

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402909

      Thumbnail image of graphical abstract

      A Pd-catalyzed cascade cyclization strategy has been documented for expedient access to the spiroindolinone–isoindolinone architecture. The Ugi-4-component reaction (Ugi-4CR) generates diversity, while Pd catalysis ensures regioselective ring closure.

    2. Desymmetrization

      First Enantioselective Catalytic Wittig Reaction

      Thomas Werner, Marcel Hoffmann and Sunetra Deshmukh

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402941

      Thumbnail image of graphical abstract

      Over 50 years after the discovery of the Wittig reaction, the first example of a catalytic enantioselective version of this reaction is reported. Desymmetrization of a prochiral ketone leads to the so-called bis-nor-Wieland–Miescher ketone in up to 90 % ee.

  11. Full Papers

    1. Organocascade Catalysis

      Catalytic Asymmetric Michael Addition/Cyclization Cascade Reaction of 3-Isothiocyanatooxindoles with Nitro Olefins

      Satavisha Kayal and Santanu Mukherjee

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402534

      Thumbnail image of graphical abstract

      The first organocatalytic asymmetric reaction of 3-isothiocyanatooxindoles with nitro olefins has been developed by using a cinchonidine-derived bifunctional catalyst. The resulting products, highly functionalized 3,2′-pyrrolidinyl spirooxindole derivatives, were obtained in high yields with good diastereo- and enantioselectivities (dr up to >20:1 and er = 96:4).

    2. Cross-Coupling

      Synthesis of Internal Alkynes by Pd(PPh3)4/TMEDA-Catalyzed Kumada Cross-Coupling of Alkynyl Halides with Grignard Reagents

      Mao-Mei Zhang, Jun Gong, Ren-Jie Song and Jin-Heng Li

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402558

      Thumbnail image of graphical abstract

      A new Pd-catalyzed Kumada cross-coupling reaction of alkynyl halides with Grignard reagents has been developed. This transformation provides a new, experimentally simple access to internal alkynes in good yields, and it can accommodate a broad range of substrates with excellent functional group tolerance and good levels of selectivity control.

    3. Protecting Groups

      Arylsulfonyl Groups: The Best Cyclization Auxiliaries for the Preparation of ATRC γ-Lactams can be Acidolytically Removed

      Andrew J. Clark, Andrea Cornia, Fulvia Felluga, Armando Gennaro, Franco Ghelfi, Abdirisak A. Isse, Maria Cristina Menziani, Francesco Muniz-Miranda, Fabrizio Roncaglia and Domenico Spinelli

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402769

      Thumbnail image of graphical abstract

      Acid removal of arylsulfonyl groups, which are the best and most useful cyclization auxiliaries for the transition-metal-catalyzed atom transfer radical cyclization (ATRC) of N-allyl-α-polychloroamides, can be effectively performed by using H2SO4 in HOAc, but the aromatic ring needs to be “electron rich”.

  12. Microreviews

    1. Aminoglycosides

      2-Nitroglycals: Versatile Building Blocks for the Synthesis of 2-Aminoglycosides

      Thierry Delaunay, Thomas Poisson, Philippe Jubault and Xavier Pannecoucke

      Article first published online: 12 SEP 2014 | DOI: 10.1002/ejoc.201402805

      Thumbnail image of graphical abstract

      Nitration of glycals gives access to the versatile 2-nitroglycal derivatives. These key building blocks are used for the synthesis of potent biologically active compounds. This review highlights the chemistry of 2-nitroglycals and their applications.

  13. Short Communications

    1. Lewis Acidity

      31P NMR Spectroscopically Quantified Hydrogen-Bonding Strength of Thioureas and Their Catalytic Activity in Diels–Alder Reactions

      Alexander R. Nödling, Gergely Jakab, Peter R. Schreiner and Gerhard Hilt

      Article first published online: 10 SEP 2014 | DOI: 10.1002/ejoc.201402871

      Thumbnail image of graphical abstract

      The correlation of 31P NMR shift values [Δδ(31P)] for the determination of hydrogen-bond strengths of thiourea derivatives with kinetic data [ln (krel)]of thiourea-catalyzed Diels–Alder reactions is evaluated. A Hammett-type plot provides a more reliable correlation than the correlation of kinetic data with the pKa values of the thiourea derivatives.

  14. Full Papers

    1. Total Synthesis

      A Convergent Synthesis of Carbocyclic Sinefungin and its C-5 Epimer

      Arun K. Ghosh and Kai Lv

      Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201402812

      Thumbnail image of graphical abstract

      A convergent synthesis of carbocyclic sinefungin (2), its C-5 epimer 3a, and adenine-modified derivative 3b is described. The key features of this approach include the use of commercially available L-methionine and readily available (1R,4S)-4-hydroxy-2-cyclopentenyl acetate, a cross-metathesis reaction, an enzymatic kinetic resolution, and a Staudinger reduction.

  15. Microreviews

    1. Vicinal Quaternary Stereocenters

      The Nazarov Cyclization: A Valuable Method to Synthesize Fully Substituted Carbon Stereocenters

      Donald R. Wenz and Javier Read de Alaniz

      Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201402825

      Thumbnail image of graphical abstract

      We describe three general approaches to the formation of fully substituted quaternary carbon stereocenters by means of the Nazarov cyclization.

  16. Short Communications

    1. Chiral Carbacycles

      One-Pot Preparation of Chiral Carbacycles from Morita–Baylis–Hillman Carbonates by an Asymmetric Allylic Alkylation/Olefin Metathesis Sequence

      Piotr Putaj, Iveta Tichá, Ivana Císařová and Jan Veselý

      Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201402899

      Thumbnail image of graphical abstract

      A one-pot synthetic protocol for the regio- and stereoselective formation of highly substituted five- and six-membered carbacycles was developed. The two-step procedure includes an asymmetric allylic alkylation (AAA) of Morita–Baylis–Hillman (MBH) carbonates followed by a ring-closing alkene metathesis (RCM) reaction and affords the corresponding carbacycles in high yields with good enantioselectivity.

    2. Cross-Coupling

      Nickel-Catalyzed Desulfitative Suzuki–Miyaura Cross-Coupling of N,N-Disulfonylmethylamines and Arylboronic Acids

      Liangshun Chen, Hongyue Lang, Lei Fang, Jianjun Yu and Limin Wang

      Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201402919

      Thumbnail image of graphical abstract

      A NiCl2(dppp)-catalyzed [dppp = 1,3-bis(diphenylphosphino)propane] desulfitative Suzuki–Miyaura cross-coupling reaction between N,N-disulfonylmethylamines and arylboronic acids is described for the first time. The biaryl compounds are obtained in moderate to good yields.

    3. Deracemization

      Deracemization of Quinolonecarboxamides by Dynamic Crystalline Salt Formation and Asymmetric Photoreaction by Using the Frozen Chirality

      Fumitoshi Yagishita, Naoya Takagishi, Hiroki Ishikawa, Yoshio Kasashima, Takashi Mino and Masami Sakamoto

      Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201403056

      Thumbnail image of graphical abstract

      Crystallization of racemic quinolonecarboxamides with enantiopure L-dibenzoyltartaric acid (L-DBTA) leads to deracemization. The axial chirality is retained for a long period of time after the salts are dissolved in cooled solvents, and this frozen chirality can be effectively transferred to the products by using a typical [2+2] photocycloaddition reaction with alkenes; CIDT = crystallization-induced diastereomer transformation.

    4. Zwitterionic Enolates

      Formation of a Zwitterionic Enolate from Tetramethylthiourea and Dimethyl Acet­ylenedicarboxylate

      Amélie Wannebroucq, Mateusz B. Pitak, Simon J. Coles and John D. Wallis

      Article first published online: 9 SEP 2014 | DOI: 10.1002/ejoc.201402807

      Thumbnail image of graphical abstract

      A zwitterionic enolate of a β-keto ester was prepared by an unusual rearrangement reaction from tetramethylthiourea and dimethyl acetylenedicarboxylate. The negative charge is delocalised more on the ketone carbonyl than on the ester group, and there is an O···C interaction between this keto O atom and the amidinium C atom of 2.608 Å. The two carbonyl groups of the enolate have a cis orientation.

  17. Full Papers

    1. Electrophilic Addition

      Regioselectivity and High Electrophilicity in the σ Complexation of Aromatic Triflones

      Nizar El Guesmi, Taoufik Boubaker, Régis Goumont and François Terrier

      Article first published online: 8 SEP 2014 | DOI: 10.1002/ejoc.201402607

      Thumbnail image of graphical abstract

      The ambident electrophilic behaviour of unsymmetrical 2-nitro-4,6-bis (trifluoromethylsulfonyl)anisole (1e) has been delineated through a kinetic and thermodynamic study of the reactions with MeO and MeOH in methanol. The results highlight the crucial role of a para-SO2CF3 group in determining the superelectrophilic reactivity of 1e and other aromatic triflones.

  18. Short Communications

    1. β-Ketonitriles

      Specific 1,2-Hydride Shift in the Boron Trifluoride Catalyzed Reactions of Aromatic Aldehydes with Diazoacetonitrile: Simple Synthesis of β-Ketonitriles

      Zhanhui Yang, Kwon-Il Son, Siqi Li, Bingnan Zhou and Jiaxi Xu

      Article first published online: 8 SEP 2014 | DOI: 10.1002/ejoc.201402901

      Thumbnail image of graphical abstract

      Under the catalysis of BF3·OEt2, the reactions of aromatic aldehydes with diazoacetonitrile proceed through nucleophilic addition and specific 1,2-hydride shift to provide a simple method to synthesize β-ketonitriles. With this method, a series of structurally diverse β-ketonitriles is readily synthesized in 48–87 % yield.

  19. Full Papers

    1. Asymmetric Catalysis

      Metallacrown Ether Catalysts Containing Phosphine–Phosphite Polyether Ligands for Rh-Catalyzed Asymmetric Hydrogenation – Enhancements in Activity and Enantioselectivity

      Feng-Tao Song, Guang-Hui Ouyang, Yong Li, Yan-Mei He and Qing-Hua Fan

      Article first published online: 8 SEP 2014 | DOI: 10.1002/ejoc.201402735

      Thumbnail image of graphical abstract

      Remarkable enhancements in enantioselectivity and activity have been achieved in the rhodium-catalyzed asymmetric hydrogenation of α-arylenamides by using tunable phosphine–phosphite-containing metallacrown ether catalysts through a host–guest recognition with alkali cations.

  20. Short Communications

    1. Trifluoromethylation

      Rapid and Selective Electrophilic Trifluoromethylation of the 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) Scaffold

      Nico Santschi, Ján Cvengroš, Coraline Matthey, Elisabeth Otth and and Antonio Togni

      Article first published online: 8 SEP 2014 | DOI: 10.1002/ejoc.201402874

      Thumbnail image of graphical abstract

      A protocol for the rapid trifluoromethylation of the BODIPY scaffold, based on a mixture of 3,3-dimethyl-1-(trifluoromethyl)-3H-1λ3,2-benziodaoxole and iPrSH, is presented. The electronic and structural changes imparted by the CF3 moiety are studied by NMR and UV/Vis spectroscopy and X-ray crystallography.

    2. Industrial Syntheses

      A Scalable Synthesis of the Antidepressant Agomelatine by a Tandem Allylic Chlorination–Isomerization Process

      Christos I. Stathakis, Efstratios Neokosmidis and Theocharis V. Koftis

      Article first published online: 8 SEP 2014 | DOI: 10.1002/ejoc.201402886

      Thumbnail image of graphical abstract

      A tandem allylic rearrangement–isomerization sequence on a tetralone-derived allyl carbinol was applied for the preparation of agomelatine, a high-potential antidepressant agent with improved pharmacokinetic profile. The active pharmaceutical ingredient (API) was obtained in 52.3 % overall yield and excellent purity (> 99.5 %) by a simple process amenable to industrial-scale applications.

  21. Full Papers

    1. Enzyme Catalysis

      Regio- and Stereoselective Lipase-Catalysed Acylation of Methyl α-D-Glycopyranosides with Fluorinated β-Lactams

      Riku Sundell, Elina Siirola and Liisa T. Kanerva

      Article first published online: 5 SEP 2014 | DOI: 10.1002/ejoc.201402800

      Thumbnail image of graphical abstract

      The lipase-catalysed diastereoselective ring-opening of aromatic and hetero-aromatic β-lactams was explored for the formation of β-amino acid conjugates of methyl α-D-glycopyranosides. Potential hydrolytic side-reactions were minimized by a suitable choice of solvent, lipase preparation and the use of molecular sieves.

    2. Macrocycles

      Facile Synthesis of 9,10,19,20-Tetraarylporphycenes

      Emandi Ganapathi, Tamal Chatterjee and Mangalampalli Ravikanth

      Article first published online: 5 SEP 2014 | DOI: 10.1002/ejoc.201402770

      Thumbnail image of graphical abstract

      A simple, rapid method was developed for the synthesis of meso-tetraarylporphycenes by employing a McMurry coupling followed by an oxidation reaction as the key steps. This synthetic strategy uses readily available precursors to afford 9,10,19,20-tetraarylporphycenes. The absorption, fluorescence, and electrochemical properties of these macrocycles were also studied.

    3. C–H Activation

      Palladium-Catalyzed Oxidative Synthesis of Aromatic Ketones Using Olefins as Acyl Equivalents through Selective ortho Aromatic C–H Bond Activation

      Ashok B. Khemnar and Bhalchandra M. Bhanage

      Article first published online: 5 SEP 2014 | DOI: 10.1002/ejoc.201402782

      Thumbnail image of graphical abstract

      A simple and efficient method has been developed for the synthesis of heteroaryl ketones by C–H activation of 2-phenylpyridine/1-phenylpyrazole, using olefins as acyl surrogates.

    4. Enzyme Catalysis

      Lipase-Catalyzed Synthesis of Substituted Phenylacetamides: Hammett Analysis and Computational Study of the Enzymatic Aminolysis

      Guadalupe García Liñares, Pau Arroyo Mañez and Alicia Baldessari

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402749

      Thumbnail image of graphical abstract

      Substituted phenylacetamides were obtained from phenylacetic acid through lipase-catalyzed esterification and aminolysis. The lipase activity in the aminolysis of phenylacetic esters depends on the substitution in the ring. 4-Nitrophenylacetic acid afforded the corresponding amides in the highest yield in a one-pot, two-step procedure. Hammett analysis and a computational study were carried out.

    5. Peroxides

      Six Peroxide Groups in One Molecule – Synthesis of Nine-Membered Bicyclic Silyl Peroxides

      Ashot V. Arzumanyan, Alexander O. Terent'ev, Roman A. Novikov, Valentin G. Lakhtin, Vladimir V. Chernyshev, Andrew N. Fitch and Gennady I. Nikishin

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402895

      Thumbnail image of graphical abstract

      Compounds containing two nine-membered peroxide rings bridged by an ethane, ethene, or ethyne group are synthesized. Each ring is formed by the replacement of two geminal chlorine atoms at the silicon atom with the hydroperoxide groups of one peroxide molecule. The peroxides are isolated by crystallization or silica gel filtration; unexpectedly, all of these compounds are extremely explosive.

    6. C–H Arylation

      Synthesis of Indole-Derived Allocolchicine Congeners through Pd-Catalyzed Intramolecular C-H Arylation Reaction

      Nikolay S. Sitnikov, Antonina S. Kokisheva, Georgy K. Fukin, Jörg-Martin Neudörfl, Hannah Sutorius, Aram Prokop, Valery V. Fokin, Hans-Günther Schmalz and Alexey Yu. Fedorov

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402850

      Thumbnail image of graphical abstract

      The synthesis of indole-derived structural analogs of natural antimitotic agent allocolchicine is reported. In a key step, an intramolecular Pd-catalyzed C–H arylation reaction serves to construct the polycyclic ring system, by connecting the two electron-rich arene fragments.

    7. Continuous Flow Microreactor

      A General Continuous Flow Method for Palladium Catalysed Carbonylation Reactions Using Single and Multiple Tube-in-Tube Gas-Liquid Microreactors

      Ulrike Gross, Peter Koos, Matthew O'Brien, Anastasios Polyzos and Steven V. Ley

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402804

      Thumbnail image of graphical abstract

      A Teflon® AF-2400 Tube-in-Tube reactor facilitates the use of carbon monoxide in continuous-flow C–C bond forming reactions providing esters, amides, carboxylic acids, lactones and lactams. Two reactors can be used in series to permit the sequential addition of two reactive gases (CO and Me2NH) into the flow stream.

    8. Asymmetric Aldol Reactions

      Asymmetric Evans syn-Aldol Reactions of Terpene-Derived Enals: Scope and Limitations

      Sebastian Kriening, Athanasios Evagelou, Birgit Claasen, Angelika Baro and Sabine Laschat

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402736

      Thumbnail image of graphical abstract

      The asymmetric Evans aldol reaction could be successfully applied to terpene-based (E)- and (Z)-aldehydes and N-acyloxazolidinones, giving syn-aldol adducts with high selectivity. Isomerization at the double bond was not observed.

    9. Chemoselectivity

      Reagent-Controlled Cyclization–Deprotection Reaction to Yield either Fluorenes or Benzochromenes

      Dan Killander and Olov Sterner

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402722

      Thumbnail image of graphical abstract

      The selective synthesis of either a benzochromene or a fluorene from the same starting material based on the choice of reagent is presented.

    10. Chelators for Bioconjugation

      Efficient Synthesis of 1,4,7-Triazacyclononane and 1,4,7-Triazacyclononane-Based Bifunctional Chelators for Bioconjugation

      Pauline Désogère, Yoann Rousselin, Sophie Poty, Claire Bernhard, Christine Goze, Frédéric Boschetti and Franck Denat

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402708

      Thumbnail image of graphical abstract

      A new synthesis of 1,4,7-triazacyclononane and its N-functionalized derivatives is described. This powerful approach outperforms previous synthetic methods due to the use of an aminal intermediate. The method can be extended to the synthesis of valuable C-functionalized building blocks, giving access to a wide range of new bifunctional chelating agents, such as the p-NCS-Bz-MA-NOTA chelator.

    11. Fluorinated Heterocycles

      Revisiting the Synthesis of 4,6-Difluoro­benzofuroxan: A Study of Its Reactivity and Access to Fluorinated Quinoxaline Oxides

      Cyril Jovené, Morgane Jacquet, Jérome Marrot, Flavien Bourdreux, Mikhail E. Kletsky, Oleg N. Burov, Anne-Marie Gonçalves and Régis Goumont

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402692

      Thumbnail image of graphical abstract

      We report on the synthesis of 4,6-difluorobenzofuroxan and on the use of this heterocycle in the synthesis of biologically active compounds. The electrophilicity of fluorinated derivatives has been studied theoretically and electrochemically. The unexpected behavior of benzoquinone 2-diazide in the Diels–Alder reaction is also reported.

    12. Cross-Coupling Reaction

      Convenient Formation of Triarylphosphines by Nickel-Catalyzed C–P Cross-Coupling with Aryl Chlorides

      Meng Sun, Yu-Shi Zang, Le-Kai Hou, Xiang-Xiang Chen, Wei Sun and Shang-Dong Yang

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402660

      Thumbnail image of graphical abstract

      A convenient strategy has been developed for the preparation of various phosphine ligands in good to excellent yields through a nickel-catalyzed C–P bond-forming step. This reaction proceeded smoothly and tolerated a variety of functional groups to provide a new method for the synthesis of important phosphine ligands through the direct cleavage of a C–Cl bond.

    13. Cyclocarbonylation

      Preparation of Cyclohexenones from Acyclic (Pentadienyl)iron(1+) Cations: Synthetic Studies Directed toward the A-Ring of Dihydrotachysterols

      Charles F. Manful and William A. Donaldson

      Article first published online: 4 SEP 2014 | DOI: 10.1002/ejoc.201402615

      Thumbnail image of graphical abstract

      The reaction of (3-methylpentadienyl)Fe(CO)3+ cation (7) with stabilized carbon nucleophiles affords cyclohexenones. Reaction of 7 with a non-racemic C2 chiral nucleophile dihydrotachysterol analogs proceeds with good diastereoselectivity. Issues in diastereoselectivity in approaches to synthons for the A-ring of the tachysterols from these cyclohexenones are reported.

    14. Asymmetric Catalysis

      Catalytic Enantioselective Addition of Aryl Grignard Reagents to Ketones

      Emilio Fernández-Mateos, Beatriz Maciá and Miguel Yus

      Article first published online: 3 SEP 2014 | DOI: 10.1002/ejoc.201402935

      Thumbnail image of graphical abstract

      The catalytic enantioselective addition of aryl Grignard reagents to ketones is now possible. Using a readily available Ar-BINMOL ligand and titanium(IV) isopropoxide in a simple, one-pot procedure under mild conditions, a wide range of aromatic ketones are converted into diaryl alcohols in good yields and with good enantioselectivities.

    15. Helicene Fluorophores

      Modular Synthesis of pH-Sensitive Fluorescent Diaza[4]helicenes

      Antoine Wallabregue, Petr Sherin, Joyram Guin, Céline Besnard, Eric Vauthey and Jérôme Lacour

      Article first published online: 3 SEP 2014 | DOI: 10.1002/ejoc.201402863

      Thumbnail image of graphical abstract

      Configurationally stable diaza[4]helicenes have been prepared by a particularly facile N–N bond-cleavage reaction using hydrazine for the introduction of a single nitrogen atom. The helical quinacridines are dyes showing absorption and emission properties in the near-IR region that depend on pH. A high racemization barrier of 30.7 ± 4.0 kcal/mol was determined for the single enantiomers.

    16. Enamides

      Synthesis of exo-Enamides from Protected Lactams Using a Modified Julia Olefination Reaction: Application to the Synthesis of Spiroaminal Fragments

      Nicolas Gigant, Samuel Habib, Marie Medoc, Peter G. Goekjian, David Gueyrard and Isabelle Gillaizeau

      Article first published online: 1 SEP 2014 | DOI: 10.1002/ejoc.201402681

      Thumbnail image of graphical abstract

      A modified Julia olefination (Julia–Kocienski) reaction involving lactams has been developed, which gives the corresponding exo-enamides in moderate to good yields. An application of this unprecedented transformation in the synthesis of spiroaminal fragments is also demonstrated.

    17. Ferrocenes

      Ferrocenes Bearing Highly Extended π Systems with Nitrile, Nitro, and Dimethylamino End Groups

      Nico Krauße and Holger Butenschön

      Article first published online: 1 SEP 2014 | DOI: 10.1002/ejoc.201402831

      Thumbnail image of graphical abstract

      New ferrocenes bearing highly extended π systems with nitrile, nitro, and dimethylamino end groups are prepared that include a push-pull-substituted system. The redox properties of the new compounds have been characterized by cyclic voltammetry.

    18. Heterocyclic Chemistry

      Two-Step Regioselective Synthesis of 3-(Sulfonylamino)imidazo[1,2-a]pyrimidines from 2-Aminopyrimidines and N-(2,2-Dichloro-2-phenylethylidene)arensulfonamides

      Igor B. Rozentsveig, Valery Yu. Serykh, Gulnur N. Chernysheva, Evgeniy V. Kondrashov, Alena I. Fedotova, Igor A. Ushakov, Evgeny V. Tretyakov and Galina V. Romanenko

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402695

      Thumbnail image of graphical abstract

      2-Aminopyrimidines react easily with electrophilic N-(arylsulfonyl)phenyldichloroacetaldimines to give the corresponding addition products of the amine moiety to the azomethine group. The obtained compounds were successfully utilized to synthesize imidazo[1,2-a]pyrimidin-3-ylsulfonamides regioselectively.

    19. Mild, Stereoselective, and Highly Efficient Synthesis of N-Acylhydrazones Mediated by CeCl3·7H2O in a Broad Range of Solvents

      José Maurício dos Santos Filho

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402609

      Thumbnail image of graphical abstract

      The stereoselective condensation of hydrazides with aldehydes or ketones to give (E)-N-acylhydrazones is a valuable approach to prepare new compounds that exhibit biological activity. A mild, easy, environmental friendly, and highly efficient method that employs CeCl3·7H2O as the catalyst was developed to provide a broad and structurally diverse library of N-acylhydrazones in excellent yields.

    20. Secondary Structure Mimetics

      Stereoselective Synthesis of Tricyclic Diproline Analogues that Mimic a PPII Helix: Structural Consequences of Ring-Size Variation

      Arne Soicke, Cédric Reuter, Matthias Winter, Jörg-Martin Neudörfl, Nils Schlörer, Ronald Kühne and Hans-Günther Schmalz

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402737

      Thumbnail image of graphical abstract

      Two new tricyclic amino acid scaffolds, which differ from the first generation scaffold by the size of ring A, were stereoselectively synthesized. The conformational analysis of the three homologous scaffolds was revealed by NMR spectroscopy.

    21. Chiral Spirocompounds

      Synthesis, Chiral Resolution, and Absolute Configuration of C2-Symmetric, Chiral 9,9′-Spirobifluorenes

      Caroline Stobe, Ryota Seto, Andreas Schneider and Arne Lützen

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402738

      Thumbnail image of graphical abstract

      Dissymmetric difunctionalised 9,9′-spirobifluorene derivatives were prepared and resolved by HPLC on a chiral stationary phase on a semipreparative scale. The absolute configurations of the resolved enantiomers were assigned by comparison of specific optical rotations with literature data or retention times of independently prepared enantiomerically pure material.

    22. Synthetic Methods

      A Base-Mediated Mild Sulfenylation of Indoles and Pyrrole with α-Acylthiones

      Caterina Viglianisi, Enrico Marcantoni, Vanessa Carapacchi, Stefano Menichetti and Laura Marsili

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402894

      Thumbnail image of graphical abstract

      A simple procedure for the sulfenylation of indoles and pyrroles through hetero-aromatic substitution with α-acylthiones acting as electrophiles is presented. The reaction occurs under mild basic conditions that are particularly suitable for the derivatization of aza-aromatics. However, such conditions are quite uncommon.

  22. Short Communications

    1. Fluorine-18-Labelled Radiotracers

      An Efficient Method for Enhancing the Reactivity and Flexibility of [18F]Fluoride Towards Nucleophilic Substitution Using Tetraethylammonium Bicarbonate

      Laurent Brichard and Franklin I. Aigbirhio

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402587

      Thumbnail image of graphical abstract

      Tetraethylammonium hydrogen carbonate proves to be a very efficient phase-transfer agent for the enhancement of the reactivity of [18F]fluoride towards nucleophilic substitution reactions with or without low amounts of water.

    2. Stereoselective Nucleophilic Addition

      Highly Stereoselective Nucleophilic Addition of Difluoromethyl-2-pyridyl Sulfone to Sugar Lactones and Efficient Synthesis of Fluorinated 2-Ketoses

      Xiao Liu, Qiang Yin, Jian Yin, Guohua Chen, Xin Wang, Qi-Dong You, Yue-Lei Chen, Bing Xiong and Jingkang Shen

      Article first published online: 29 AUG 2014 | DOI: 10.1002/ejoc.201402757

      Thumbnail image of graphical abstract

      Nucleophilic addition of difluoromethyl-2-pyridyl sulfone to sugar lactones gave intermediates that are stable and capable of useful conversions. Formal elimination of the anomeric hydroxy and sulfonyl groups yielded a 1-deoxy-1-difluoromethylene mannopyranose derivative. Fluorinated 2-ketose analogues were prepared by a one-pot reduction with allylmagnesium chloride.

    3. Nonmetallic Alcohol Oxidation

      Organocatalytic Oxidation of Secondary Alcohols Using 1,2-Di(1-naphthyl)-1,2-ethanediamine (NEDA)

      Afnan Al-Hunaiti, Minna Räisänen, Petri Pihko, Markku Leskelä and Timo Repo

      Article first published online: 27 AUG 2014 | DOI: 10.1002/ejoc.201402991

      Thumbnail image of graphical abstract

      A nonmetal catalytic oxidation of alcohols with preferential oxidation of secondary alcohols by diamine is developed. 1,2-Di(1-naphthyl)-1,2-ethanediamine (NEDA) is used as catalyst to selectively oxidize secondary alcohols in the presence of TBHP as terminal oxidant. The chiral NEDA is also studied and shows promising enantioselectivity in oxidative kinetic resolution of racemic secondary alcohols with good to excellent ee values.

    4. C–H Insertions

      Synthesis of N-(2,3,4,5,6-Pentafluorobenzyloxy)-γ-lactams by Rhodium-Catalyzed Cyclization of Diazo Amides

      Marcin Budny, Magdalena Nowak, Andrzej Wojtczak and Andrzej Wolan

      Article first published online: 27 AUG 2014 | DOI: 10.1002/ejoc.201402571

      Thumbnail image of graphical abstract

      The rhodium-catalyzed cyclization of diazo amides, derived from O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine, is reported. The reaction leads to a variety of lactams in up to 91 % yield and 88 % ee. The developed method was applied in the synthesis of gabapentin hydrochloride, an important GABA analog.

  23. Full Papers

    1. Tandem Reactions

      LiAlH4-Promoted Tandem Reduction/Oxidation of Fluorenyl Derivatives Under Air

      Tetiana Matviiuk, Christophe Menendez, Chantal Carayon, Nathalie Saffon, Zoia Voitenko, Christian Lherbet and Michel Baltas

      Article first published online: 27 AUG 2014 | DOI: 10.1002/ejoc.201402642

      Thumbnail image of graphical abstract

      The tandem reduction/oxidation of fluorenyl compounds with LiAlH4 under air affords the corresponding 9-hydroxyfluorenyl derivatives in good yields.

    2. Iminosugar Disaccharides

      Stereoselective Access to the β-D-N-Acetylhexosaminyl-(1[RIGHTWARDS ARROW]4)-1-deoxy-D-nojirimycin Disaccharide Series Avoiding the Glycosylation Reaction

      Lorenzo Guazzelli, Giorgio Catelani, Felicia D'Andrea, Tiziana Gragnani and Alessio Griselli

      Article first published online: 27 AUG 2014 | DOI: 10.1002/ejoc.201402555

      Thumbnail image of graphical abstract

      The title disaccharides of four stereoseries were prepared through an approach that does not require a glycosylation step. Starting from known compounds, all obtained from lactose, the DNJ unit was constructed through C-5 oxidation of the reducing D-glucopyranosyl unit followed by a stereoselective double-reductive aminocyclisation of the 1,5-dicarbonyl disaccharide intermediates.

  24. Microreviews

    1. Complementary Recognition Sites

      Supramolecular Control of Reactivity and Catalysis – Effective Molarities of Recognition-Mediated Bimolecular Reactions

      Stefano Di Stefano, Roberta Cacciapaglia and Luigi Mandolini

      Article first published online: 26 AUG 2014 | DOI: 10.1002/ejoc.201402690

      Thumbnail image of graphical abstract

      Effective molarities (EM) of intramolecular reactions in 1:1 supramolecular complexes are critically surveyed and analyzed in terms of entropy and strain.

  25. Full Papers

    1. Natural Product Synthesis

      A Common Synthetic Protocol for the Cyclic and Acyclic Core of Migrastatin, Isomigrastatin, and Dorrigocin via a Chiral β-Hydroxy-γ-butyrolactone Intermediate

      Narendar Reddy Gade and Javed Iqbal

      Article first published online: 26 AUG 2014 | DOI: 10.1002/ejoc.201402830

      Thumbnail image of graphical abstract

      The synthesis of a key intermediate chiral β-hydroxy-γ-butyrolactone (A) by PdII-catalysed stereoselective allylic C–H oxidation is reported. A common synthetic route to transform this intermediate into key building blocks for the synthesis of migrastatin family members has been developed.

    2. C–N Bond Formation

      Selective C–N Bond-Forming Reaction of 2,6-Dibromopyridine with Amines

      Lei Wang, Ning Liu, Bin Dai and Hengcai Hu

      Article first published online: 26 AUG 2014 | DOI: 10.1002/ejoc.201402619

      Thumbnail image of graphical abstract

      A practical protocol for the syntheses of 6-substituted 2-bromopyridine compounds has been developed by using a selective copper-catalyzed coupling reaction of 2,6-dibromopyridine with a range of amines.

    3. Maillard-Type Condensation

      Synthesis of the Revised Structure of Acortatarin A

      Hui Min Geng, Louise A. Stubbing, Jack Li-yang Chen, Daniel P. Furkert and Margaret A. Brimble

      Article first published online: 25 AUG 2014 | DOI: 10.1002/ejoc.201403000

      Thumbnail image of graphical abstract

      The use of a novel Maillard-type condensation between a primary amine derived from D-mannitol and a dihydropyranone as a key step to access the unusual morpholine-spiroketal acortatarin A is reported. The approach also allows access to a C-2 analogue, and can be used for synthesis of related 2-formylpyrrole natural products.

    4. Atropisomerism

      A Planar-Chiral Phosphino(alkenyl)ferrocene for Suzuki–Miyaura C–C Coupling Reactions

      Dieter Schaarschmidt, Martin Grumbt, Alexander Hildebrandt and Heinrich Lang

      Article first published online: 22 AUG 2014 | DOI: 10.1002/ejoc.201402861

      Thumbnail image of graphical abstract

      Planar-chiral phosphino(alkenyl)ferrocene 4 was applied in the presence of [Pd2(dba)3] in Suzuki–Miyaura C–C coupling reactions for the atropselective synthesis of sterically congested biaryls with up to four substituents in the ortho-positions. The air-stable catalytic system is excellently suited for the synthesis of tri-ortho-substituted biaryls under mild conditions (0.1 mol-%, 50–100 °C).

    5. Fused Heterocycles

      A K2CO3-Mediated Regioselective Synthesis of Indole/Pyrrole-Fused 1,4-Oxazines: An Unexpected Indole-Fused Azlactone Synthesis

      Jaya Kishore Vandavasi, Wan-Ping Hu, Gopal Chandru Senadi, Siva Senthil Kumar Boominathan, Hsing-Yin Chen and Jeh-Jeng Wang

      Article first published online: 22 AUG 2014 | DOI: 10.1002/ejoc.201402818

      Thumbnail image of graphical abstract

      A regioselective, base-catalyzed 6-exo-dig cyclization has been developed for the synthesis of indole- and pyrrole-fused 1,4-oxazines. In addition, an unprecedented one-pot hydroamination reaction was observed to occur with high chemo- and regioselectivity in the presence of base to afford indole-fused azlactones.

    6. Atroposelectivity

      A Concise Atroposelective Formal Synthesis of (–)-Steganone

      Boubacar Yalcouye, Sabine Choppin, Armen Panossian, Frédéric R. Leroux and Françoise Colobert

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402761

      Thumbnail image of graphical abstract

      A highly atroposelective formal synthesis of (–)-steganone is described highlighting the use of an enantiopure sulfoxide as a chiral auxiliary in the Suzuki–Miyaura cross-coupling reaction.

    7. Asymmetric Catalysis

      Organocatalytic Enantioselective Strecker Reaction of Imines Containing a Thiazole Moiety by Using a Cinchona-Based Squaramide Catalyst

      Hai-Xiao He and Da-Ming Du

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402764

      Thumbnail image of graphical abstract

      An organocatalytic enantioselective Strecker reaction was developed for the synthesis of α-amino nitriles that contain a thiazole moiety by using a cinchona-based squaramide catalyst. The corresponding products were obtained in good to excellent yields (up to 99 %) with excellent enantioselectivities (up to 98 % ee) by starting from aromatic-substituted imines.

    8. Star-Shaped Compounds

      Modular Syntheses of Star-Shaped Pyridine, Bipyridine, and Terpyridine Derivatives by Employing Sonogashira Reactions

      Daniel Trawny, Valentin Kunz and Hans-Ulrich Reissig

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402778

      Thumbnail image of graphical abstract

      Modular, simple, and efficient! A library of C3-symmetrical compounds with benzene cores and pyridine, bipyridine, and terpyridine end groups were prepared from simple precursors.

    9. Natural Product Synthesis

      Flexible Synthesis of Planar Chiral Azoninones and Optically Active Indolizidinones

      Frank Bohland, Irina Erlin, Lukas Platte, Maike Schröder, Dieter Schollmeyer and Udo Nubbemeyer

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402720

      Thumbnail image of graphical abstract

      L-Proline derivatives were used to synthesise optically active 2-vinylpyrrolidines with E and Z double bonds. Zwitterionic aza-Claisen rearrangements led to planar chiral azoninones with defined configurations, which served as key intermediates for the synthesis of indolizidinones with up to five stereogenic centres.

    10. Enzymatic Transesterification

      Diesterification of 3-[(β-Cyclodextrinyl)succinamido]propane-1,2-diol Catalysed by Lipase: Diastereoselectivity or Tridimensional Substrate Specificity?

      Cédric Gervaise, Véronique Bonnet, Florian Nolay, Christine Cézard, Imane Stasik, Catherine Sarazin and Florence Djedaïni-Pilard

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402414

      Thumbnail image of graphical abstract

      Two diastereoisomers of 3-[(β-cyclodextrinyl)succinamido]propane-1,2-diol have been transesterified with fatty esters and immobilized lipase from Mucor miehei. They react with different conversions, contrary to their analogues without cyclodextrins. The hydrogen bonds in the three-dimensional structures, which account for this phenomenon, are revealed by molecular modelling and NMR studies.

    11. Silica-Supported Catalysts

      Rhodium-NHC Hybrid Silica Materials as Recyclable Catalysts for [2+2+2] Cycloaddition Reactions of Alkynes

      Martí Fernández, Meritxell Ferré, Anna Pla-Quintana, Teodor Parella, Roser Pleixats and Anna Roglans

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402649

      Thumbnail image of graphical abstract

      Hybrid silica materials derived from rhodium(I) complexes bearing an N-heterocyclic carbene ligand are obtained either by sol-gel or grafting processes. The materials are fully characterized by solid state NMR, N2-sorption measurements, thermogravimetric analysis and elemental analysis; their catalytic activity and recyclability are also evaluated in the [2+2+2] cycloaddition of alkynes.

    12. Heterocyclic Ketene Aminals

      Isomerization of Ninhydrin–Heterocyclic Ketene Aminal Adducts: Kinetic versus Thermodynamic Control, Solvent Dependency and Mechanism

      Nanyang Chen, Minming Zou, Xue Tian, Fengjuan Zhu, Danping Jiang, Jiagao Cheng, Xusheng Shao and Zhong Li

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402677

      Thumbnail image of graphical abstract

      The first example of isomerization of ninhydrin–heterocyclic ketene aminals adducts is reported. The isomerization shows large solvent dependency and provides an efficient method with which to access hitherto undisclosed indeno[2,1-b]pyrrol-8(1H)-ones. Reaction products can now be regulated based on kinetic and thermodynamic selection principles.

    13. Synthetic Methods

      Development and Optimization of Simple One-Step Methods for the Synthesis of 4-Amino-Substituted 1,8-Naphthalimides

      Tomas Kindahl, Elin Chorell and Erik Chorell

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402684

      Thumbnail image of graphical abstract

      One-step methods for the synthesis of 4-amino-substituted 1,8-naphthalimides have been developed and optimized by using multivariate studies of temperature, reaction time and equivalents of substrates. The identified conditions could successfully be applied to generate various 4-amino-substituted 1,8-naphthalimides in high yields.

    14. Natural Product Reassignment

      Toward the Total Synthesis of Klaivanolide: Complete Reinterpretation of Its Originally Assigned Structure

      Laurent Ferrié, Sabrina Ferhi, Guillaume Bernadat and Bruno Figadère

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402741

      Thumbnail image of graphical abstract

      Attempts towards the total synthesis of uncommon seven-membered ring lactone klaivanolide led us to revise its original structural assignment. The isolated compound was revealed to be a known molecule, the five-membered ring acetylmelodorinol.

    15. Cytotoxic Nucleosides

      Trifluoromethylated Nucleosides: A Building Block Approach to Cytotoxic Adenosine Analogues

      Johannes Drexler and Ulrich Groth

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402755

      Thumbnail image of graphical abstract

      Adenosine analogues based on the 7-deazapurine motif were synthesized using synthons, allowing for introduction of a diverse set of substituents, including fluorinated moieties. Analogue cytotoxicities were determined against HeLa S3 and Hep G2 cancer cell lines and compared with the structurally similar agent tubercidin; one lead structure with nM bioactivity was identified.

    16. Organogelators

      Linear Oligocarbazole-Based Organogelators: Synthesis and Fluorescent Probing of Explosives

      Guanghui Hong, Chong Qian, Pengchong Xue, Xingliang Liu, Qingqing Wang, Mingyang Liu, Peng Gong and Ran Lu

      Article first published online: 18 AUG 2014 | DOI: 10.1002/ejoc.201402565

      Thumbnail image of graphical abstract

      The first simple carbazole-based organogelator C1 has been synthesized and can self-assemble into nanofibers through π–π interactions. Moreover, the new linear carbazole-based trimer C3 and pentamer C5 with extended conjugation also formed gels in some organic solvents upon ultrasound stimulation, and blue-emitting nanofibers based on C3 detected vapors of TNT and DNT by fluorescent quenching.

    17. Regioselectivity Switching

      Palladium-Catalyzed Regioselective 5-exo-O-Cyclization/Oxidative Heck Cascades from o-Alkynylbenzamides and Electron-Deficient Alkenes

      Youssef Madich, Rosana Álvarez and José M. Aurrecoechea

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402709

      Thumbnail image of graphical abstract

      Oxycyclization/oxidative Heck cascade reactions between o-alkynylbenzamides and electron-deficient alkenes have a cyclization regiochemistry that is catalyst dependent. Thus, the 6-endo-regioselectivity reported for a PdCl2(PPh3)2 catalyst becomes a preference for 5-exo-products when Pd(OAc)2 is used.

    18. Perfluoroalkylation

      A General, Regiospecific Synthetic Route to Perfluoroalkylated Arenes via Arene­diazonium Salts with RFCu(CH3CN) Complexes

      Dong-Fang Jiang, Chao Liu, Yong Guo, Ji-Chang Xiao and Qing-Yun Chen

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402820

      Thumbnail image of graphical abstract

      Acetonitrile is used as a ligand to stabilize perfluorocopper species by forming RFCu(CH3CN) complexes. Arenediazonium salts successfully react with this complex, leading to the regiospecific perfluoroalkylation of arenes. A wide range of functional groups are tolerated in the reaction.

    19. Total Synthesis

      Total Synthesis of a Pyrrole Lactone Alkaloid, Longanlactone

      Chada Raji Reddy, Motatipally Damoder Reddy and Uredi Dilipkumar

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402563

      Thumbnail image of graphical abstract

      The first total synthesis of a new pyrrole lactone alkaloid, longanlactone, along with its C-4 epimer is achieved from the natural amino acid L-aspartic acid with a Barbier-type propargylation and a Paal–Knorr pyrrole synthesis as key steps.

    20. Natural Product Synthesis

      Asymmetric Formal Synthesis of (+)-­Lactacystin

      Chirumarry Sridhar, Bodduri V. D. Vijaykumar, Laghuvarapu Radhika, Dong-Soo Shin and Srivari Chandrasekhar

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402700

      Thumbnail image of graphical abstract

      A formal synthesis of (+)-lactacystin was achieved from readily available isobutyraldehyde and ethyl acrylate by using a Baylis–Hillman reaction, an intermolecular nucleophilic displacement under Mitsunobu conditions, a Sharpless asymmetric epoxidation, a palladium-catalyzed syn-selective ring opening of an epoxide, an azide reductive lactamization, and a ruthenium-catalyzed oxidation as the key steps.

    21. Two-Photon Chromophores

      Synthesis and Two-Photon Absorption Properties of Ladder-Type Chromophores with Functionalized Pyrazine Units Fused as the End-Groups

      Tzu-Chau Lin, Bo-Kai Tsai, Yi-You Liu and Ming-Yu Tsai

      Article first published online: 14 AUG 2014 | DOI: 10.1002/ejoc.201402622

      Thumbnail image of graphical abstract

      Three multipolar chromophores based on ladder-type units as the central π-bridges with functionalized pyrazine moieties fused as the end-groups were synthesized for study of two-photon absorption (2PA). The π-conjugation length of the central oligo-p-phenylene component is closely related to the magnitude of 2PA, and such a structural motif provides access to highly efficient nonlinear absorbers.

    22. Fullerene Derivatives

      Reactions of [60]Fullerene with Halides and Amino Acids to Synthesize Fullero­pyrrolidines

      Bo Jin, Juan Shen, Rufang Peng, Congdi Chen and Shijin Chu

      Article first published online: 14 AUG 2014 | DOI: 10.1002/ejoc.201402655

      Thumbnail image of graphical abstract

      Fulleropyrrolidines bearing ArCH moieties were obtained in reactions between C60, the appropriate benzyl chlorides, and amino acids. A detailed investigation of these reactions resulted in the discovery of other halides, such as allyl chlorides, propargyl bromides, ethyl bromoacetate, bromoacetonitrile, and alkyl bromides, that also reacted with C60 and amino acids to produce fulleropyrrolidines.

  26. Microreviews

    1. Solar Cell Photosensitizers

      Multi-Branched Multi-Anchoring Metal-Free Dyes for Dye-Sensitized Solar Cells

      Norberto Manfredi, Bianca Cecconi and Alessandro Abbotto

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402422

      Thumbnail image of graphical abstract

      Multi-branched multi-anchoring organic dyes represent a recent new class of metal-free photosensitizers for dye-sensitized solar cells of increasing interest. The article describes design strategies, synthetic routes and optical and photovoltaic properties. The multi-branched geometry is able to induce unique features that in turn give rise to relevant photovoltaic properties.

    2. Hydroamination

      Efficient Anti-Markovnikov-Selective Catalysts for Intermolecular Alkyne Hydroamination: Recent Advances and Synthetic Applications

      Jacky C. -H. Yim and Laurel L. Schafer

      Article first published online: 28 JUL 2014 | DOI: 10.1002/ejoc.201402300

      Thumbnail image of graphical abstract

      Hydroamination, the catalytic addition of an N–H bond across a C–C unsaturation site, is a 100 % atom-economical route for the construction of nitrogen-containing small molecules. However, regioselectivity is a great challenge for this reaction. This Microreview focuses on recent advances and highlights some synthetic applications of anti-Markovnikov-selective intermolecular alkyne hydroamination.

    3. Halonitro Compounds

      Recent Developments in the Chemistry of gem-Halonitro Compounds

      Raquel G. Soengas, Rita C. Acúrcio and Artur M. S. Silva

      Article first published online: 17 JUL 2014 | DOI: 10.1002/ejoc.201402043

      Thumbnail image of graphical abstract

      gem-Halonitro compounds have important practical applications in biology and industry and are also valuable synthetic intermediates of growing chemical interest. In the past few years these derivatives have come to be recognized as powerful synthetic tools. In this review we discuss recent developments in the chemistry of gem-halonitro compounds.

    4. Organic Solar Cells

      Organometallic Approaches to Conjugated Polymers for Plastic Solar Cells: From Laboratory Synthesis to Industrial Production

      Giuseppe Marzano, Cosimo V. Ciasca, Francesco Babudri, Gabriele Bianchi, Andrea Pellegrino, Riccardo Po and Gianluca M. Farinola

      Article first published online: 1 JUL 2014 | DOI: 10.1002/ejoc.201402226

      Thumbnail image of graphical abstract

      Current organometallic approaches to the synthesis of polymers for plastic solar cells are reviewed, with emphasis also on the requirements for industrial scale-up. The number of synthetic steps for obtaining monomers, the efficiency of the polymerization protocols, and structural simplicity are key to making organic photovoltaics a viable energy source.

    5. Task-Specific Ionic Liquids

      Point-Functionalization of Ionic Liquids: An Overview of Synthesis and Applications

      Cinzia Chiappe and Christian Silvio Pomelli

      Article first published online: 27 JUN 2014 | DOI: 10.1002/ejoc.201402093

      Thumbnail image of graphical abstract

      The versatility of ionic liquids can be conveniently exploited by introducing specific functional groups at selected positions of the cation or anion. These salts (task-specific ionic liquids) can be synthesized through simple and straightforward procedures.

    6. Enantioselective Protonation

      Progress in Catalytic Asymmetric Protonation

      Sylvain Oudeyer, Jean-François Brière and Vincent Levacher

      Article first published online: 22 MAY 2014 | DOI: 10.1002/ejoc.201402213

      Thumbnail image of graphical abstract

      This review provides an overview of recent advances in catalytic enantioselective protonation of preformed enol derivatives and catalytically generated enolates or equivalents through various cascade reaction sequences giving access to a large range of enantioenriched compounds containing tertiary stereocentres.

VIEW

  1. 1 - 92

SEARCH

SEARCH BY CITATION